import { Helper } from "../core/helper";
import { MemoryStream } from "../core/memory";

const sbox: number[] = [
  0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
  0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
  0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
  0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
  0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
  0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
  0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
  0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
  0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
  0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
  0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60, 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
  0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
  0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
  0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
  0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
  0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48,
];
const sm4_FK: number[] = [
  0x00a3b1bac6, 0x0056aa3350, 0x00677d9197, 0x00b27022dc
];
const sm4_CK: number[] = [
  0x0000070e15, 0x001c232a31, 0x00383f464d, 0x00545b6269,
  0x0070777e85, 0x008c939aa1, 0x00a8afb6bd, 0x00c4cbd2d9,
  0x00e0e7eef5, 0x00fc030a11, 0x00181f262d, 0x00343b4249,
  0x0050575e65, 0x006c737a81, 0x00888f969d, 0x00a4abb2b9,
  0x00c0c7ced5, 0x00dce3eaf1, 0x00f8ff060d, 0x00141b2229,
  0x0030373e45, 0x004c535a61, 0x00686f767d, 0x00848b9299,
  0x00a0a7aeb5, 0x00bcc3cad1, 0x00d8dfe6ed, 0x00f4fb0209,
  0x0010171e25, 0x002c333a41, 0x00484f565d, 0x00646b7279,
];
class SM4_CTX {
  public key: number[];
  public rk: number[];
  public block: number[];
  public K: number[];
  public Rlt: number[];
  public Rlt_bytes: number[];

  public constructor() {
    this.rk = new Array(32);
    this.block = new Array(4);
    this.K = new Array(36);
    this.Rlt = new Array(4);
    this.Rlt_bytes = new Array(16);
  }
}

export class SM4 {
  public constructor() {
    this.ctx = new SM4_CTX();
  }
  public static getsbox(a: number) {
    let B = 0;
    for (let i = 0; i < 4; i++, a >>>= 8) B |= Helper.uint(sbox[a & 0xff] << i * 8);
    return B >>> 0;
  }
  public static linearTransform(B: number) {
    return B ^ Helper.ROLT(B, 2) ^ Helper.ROLT(B, 10) ^ Helper.ROLT(B, 18) ^ Helper.ROLT(B, 24);
  }
  public static compositeTransform(X: number) {
    return SM4.linearTransform(SM4.getsbox(X));
  }
  public static linearTransform2(B: number) {
    return B ^ Helper.ROLT(B, 13) ^ Helper.ROLT(B, 23);
  }
  public static compositeTransform2(X: number) {
    return this.linearTransform2(this.getsbox(X));
  }
  public static _setRK(ctx: SM4_CTX, reverse: boolean) {
    let i = 0;
    ctx.K[0] = Helper.byte2uint(ctx.key, 0) ^ sm4_FK[0];
    ctx.K[1] = Helper.byte2uint(ctx.key, 4) ^ sm4_FK[1];
    ctx.K[2] = Helper.byte2uint(ctx.key, 8) ^ sm4_FK[2];
    ctx.K[3] = Helper.byte2uint(ctx.key, 12) ^ sm4_FK[3];
    for (i = 0; i < 32; i++) ctx.rk[reverse ? 31 - i : i] = ctx.K[(i + 4)] = ctx.K[i] ^ SM4.compositeTransform2(ctx.K[i + 1] ^ ctx.K[i + 2] ^ ctx.K[i + 3] ^ sm4_CK[i]);
  }
  public static setRK(ctx: SM4_CTX) {
    SM4._setRK(ctx, false);
  }
  public static setRK_reverse(ctx: SM4_CTX) {
    SM4._setRK(ctx, true);
  }
  public static iterate32(ctx: SM4_CTX) {
    ctx.K[0] = ctx.block[0];
    ctx.K[1] = ctx.block[1];
    ctx.K[2] = ctx.block[2];
    ctx.K[3] = ctx.block[3];

    for (var i = 0; i < 32; i++)  ctx.K[i + 4] = ctx.K[i] ^ SM4.compositeTransform(ctx.K[i + 1] ^ ctx.K[i + 2] ^ ctx.K[i + 3] ^ ctx.rk[i]);

    ctx.Rlt[0] = ctx.K[35];
    ctx.Rlt[1] = ctx.K[34];
    ctx.Rlt[2] = ctx.K[33];
    ctx.Rlt[3] = ctx.K[32];
  }
  public static done_oneblock(ctx: SM4_CTX) {
    for (var i = 0; i < 16; i++) ctx.Rlt_bytes[i] = (ctx.Rlt[i >> 2] >> ((3 - i % 4) << 3)) & 0xff;
  }
  public ctx: SM4_CTX;
  public SetKey(key: number[]) {
    this.ctx.key = key;
  }
  public New() {
    for (var i = 0; i < 16; i++) this.ctx.Rlt_bytes[i] = 0;
  }
  public EncryptOne(data: number[]): number[] {
    this.ctx.block[0] = Helper.byte2uint(data, 0);
    this.ctx.block[1] = Helper.byte2uint(data, 4);
    this.ctx.block[2] = Helper.byte2uint(data, 8);
    this.ctx.block[3] = Helper.byte2uint(data, 12);
    SM4.setRK(this.ctx);
    SM4.iterate32(this.ctx);
    SM4.done_oneblock(this.ctx);
    return this.ctx.Rlt_bytes;
  }
  public DecryptOne(data: number[]): number[] {
    this.ctx.block[0] = Helper.byte2uint(data, 0);
    this.ctx.block[1] = Helper.byte2uint(data, 4);
    this.ctx.block[2] = Helper.byte2uint(data, 8);
    this.ctx.block[3] = Helper.byte2uint(data, 12);
    SM4.setRK_reverse(this.ctx);
    SM4.iterate32(this.ctx);
    SM4.done_oneblock(this.ctx);
    return this.ctx.Rlt_bytes;
  }
  public Encrypt(data: number[]): number[] {
    let len = data.length + 4;
    if (len % 16 == 0) len -= 16;
    else if (len % 16 < 4) len -= len % 16 + 16;
    else len -= len % 16;

    var key = new Array(16);
    Helper.ArrayCopy(this.ctx.key, key, 16);

    let mem = new MemoryStream();

    for (let i = 0; i < len; i += 16) {
      this.ctx.block[0] = Helper.byte2uint(data, i);
      this.ctx.block[1] = Helper.byte2uint(data, i + 4);
      this.ctx.block[2] = Helper.byte2uint(data, i + 8);
      this.ctx.block[3] = Helper.byte2uint(data, i + 12);

      for (var ikey = 0; ikey < 16; ikey++) this.ctx.key[ikey] ^= this.ctx.Rlt_bytes[ikey];
      SM4.setRK(this.ctx);
      SM4.iterate32(this.ctx);
      SM4.done_oneblock(this.ctx);
      mem.Write(this.ctx.Rlt_bytes, 0, 16);
    }

    let raw = new Array(32);
    let ix = data.length - len;
    if (len < data.length) Helper.ArrayCopy2(data, len, raw, 0, ix);
    Helper.ArrayCopy2(Helper.uint2byte(data.length), 0, raw, ix, 4);

    this.ctx.block[0] = Helper.byte2uint(raw, 0);
    this.ctx.block[1] = Helper.byte2uint(raw, 4);
    this.ctx.block[2] = Helper.byte2uint(raw, 8);
    this.ctx.block[3] = Helper.byte2uint(raw, 12);

    for (let ikey = 0; ikey < 16; ikey++) this.ctx.key[ikey] ^= this.ctx.Rlt_bytes[ikey];
    SM4.setRK(this.ctx);
    SM4.iterate32(this.ctx);
    SM4.done_oneblock(this.ctx);
    mem.Write(this.ctx.Rlt_bytes, 0, 16);

    if (ix + 4 > 16) {
      this.ctx.block[0] = Helper.byte2uint(raw, 16);
      this.ctx.block[1] = Helper.byte2uint(raw, 20);
      this.ctx.block[2] = Helper.byte2uint(raw, 24);
      this.ctx.block[3] = Helper.byte2uint(raw, 28);

      for (var ikey = 0; ikey < 16; ikey++) this.ctx.key[ikey] ^= this.ctx.Rlt_bytes[ikey];
      SM4.setRK(this.ctx);
      SM4.iterate32(this.ctx);
      SM4.done_oneblock(this.ctx);
      mem.Write(this.ctx.Rlt_bytes, 0, 16);
    }

    Helper.ArrayCopy(key, this.ctx.key, 16);
    return mem.ToArrary();
  }
  public Decrypt(data: number[]): number[] {
    let key = new Array(16);
    Helper.ArrayCopy(this.ctx.key, key, 16);
    let len = data.length;

    var mem = new MemoryStream();

    this.ctx.block[0] = Helper.byte2uint(data, 0);
    this.ctx.block[1] = Helper.byte2uint(data, 4);
    this.ctx.block[2] = Helper.byte2uint(data, 8);
    this.ctx.block[3] = Helper.byte2uint(data, 12);

    SM4.setRK_reverse(this.ctx);
    SM4.iterate32(this.ctx);
    SM4.done_oneblock(this.ctx);
    mem.Write(this.ctx.Rlt_bytes, 0, 16);

    for (let i = 16; i < len; i += 16) {
      this.ctx.block[0] = Helper.byte2uint(data, i);
      this.ctx.block[1] = Helper.byte2uint(data, i + 4);
      this.ctx.block[2] = Helper.byte2uint(data, i + 8);
      this.ctx.block[3] = Helper.byte2uint(data, i + 12);

      for (let ikey = 0; ikey < 16; ikey++) this.ctx.key[ikey] ^= data[i + ikey - 16];
      SM4.setRK_reverse(this.ctx);
      SM4.iterate32(this.ctx);
      SM4.done_oneblock(this.ctx);
      mem.Write(this.ctx.Rlt_bytes, 0, 16);
    }
    len = 16 + 4;
    if (data.length < len) len = 16;
    var raw = new Array(len);
    mem.Position = mem.length - len;
    mem.Read(raw, 0, len);

    while (raw[len - 1] == 0) len--;
    var byteslength = Helper.byte2uint(raw, len - 4);
    mem.SetLength(byteslength);

    Helper.ArrayCopy(key, this.ctx.key, 16);
    return mem.ToArrary();
  }
}
